The high prevalence of HIV among African American men, including men who have sex with men (MSM) is well documented. Generally the MSM population has been difficult to access and link with HIV prevention, treatment and care services. The goal of this project is to identify effective strategies for increasing the number and percentage of HIV positive African American MSM who are identified and linked with prevention, treatment, and care services. The proposed research project represents collaboration between the Baltimore City Health Department (BCHD) and The Johns Hopkins Adolescent Health Research Group (AHRG). Together, BCHD and AHRG have the experience, skills knowledge and resources to carry out the proposed research. [unreadable] [unreadable] The first specific aim is to compare the relative effectiveness of (a) partner counseling and referral services (PCRS); (b) alternative venue testing (AVT); and (c) social network interviews in form of respondent driven sampling (RDS) for reaching and motivating previously undiagnosed 18-64 year old African American men who have sex with men (MSM) to be tested and linked to medical care and prevention services. The relative effectiveness of each strategy will be determined on the basis of the following: total number of African American MSM tested; risk behaviors of those tested; total number previously undiagnosed HIV- positive African American MSM identified; and total number of previously undiagnosed HIV-positive African American MSM linked with medical care and prevention services. The second specific aim is to evaluate the relative costs of identifying each previously undiagnosed HIV-positive African American MSM for each strategy. [unreadable] [unreadable] The proposed project will build on the BCHD/AHRG current strategies to reach African American MSM including STD Clinic counseling and testing services (CTS), PCRS and AVT. In the proposed project, we will add RDS as a strategy to reach and provide CTS to social contacts of HIV positive African American MSM. The proposed project will utilize an adapted version of the PLACES methodology to enhance the selection of venues for AVT, will alternately assign HIV positive African American MSM to traditional PCRS or RDS, monitor outcomes, and compile cost estimates for the various strategies. All HIV positive and high risk negative men identified will be linked with HIV prevention, treatment, and care services. [unreadable] [unreadable] [unreadable]